Mariano Rivera saved his 31st postseason game last night, adding to his major-league record. But he never had one quite like this.

Earlier in the day, in Panama, Rivera buried two relatives who were electrocuted on his property Saturday. Last night, he recorded the final four outs in the Yankees’ wild 10-7 win over the Red Sox in ALCS Game 1 at sold-out Yankee Stadium.

Rivera, who flew back to New York on a private plane arranged and paid for ($30,000) by the Yankees, arrived at the Stadium at 8:51 p.m. while the Yankees were batting in the second.

He surfaced in the bullpen in the home fifth and was hugged by his fellow relievers.

When the Yankees built an 8-0 lead, it appeared Rivera wasn’t going to be needed.

However, after the Red Sox rallied for five runs in the seventh and two in the eighth to make it 8-7, Rivera was summoned to get the final four outs.

“It took a lot for him to go out there tonight,” Yankee captain Derek Jeter said. “He’s the most mentally tough person I’ve ever played with.”

The victory – which gave the Yankees a 1-0 lead in the best-of-seven series that resumes tonight with Jon Lieber facing Pedro Martinez – came after Yankee starter Mike Mussina was perfect for 61/3 innings.

“Turns out, we really needed him,” Mussina said of Rivera. “I’m sure glad he came back. I know it was tough for him. I know it’s been an emotional few days.”

Red Sox starter Curt Schilling took the loss – lasting just three innings on a bum ankle. He gave up six runs, throwing just 58 pitches.

He’s iffy for the rest of the series.

In the Yankee eighth, Bernie Williams’ two-out, two-run triple in the eighth hiked the lead to 10-7 and gave Rivera three runs to navigate the ninth.

He gave up two singles but got Bill Mueller to hit into a game-ending 1-6-3 double play.

Hideki Matsui tied an ALCS record with five RBIs and had three hits. Gary Sheffield went 3-for-4 and scored four runs.

Less than 24 hours after wanting to muzzle Yankees fans, Schilling was doubting his ability to pitch again in the series.

“If I can’t go out there with something better than tonight I am not going back out there,” Schilling said. “It’s not about me, it’s about winning a world championship. If I can’t do better than that, I won’t take the ball again.”

While Schilling was shelled, Mussina toyed with the Red Sox until the seventh, when he allowed his first baserunner and didn’t finish the frame in which the Bosox plated five runs to cut an 8-0 Yankees lead to 8-5.

In the eighth, Tom Gordon gave up singles to Mueller and Manny Ramirez to put runners at the corners with two outs for David Ortiz, the potential tying run. His fly to the left-center field wall almost was caught by Matsui but fell to the warning track as Mueller and Ramirez scampered home and Ortiz lumbered to third.

Joe Torre called for Rivera to face Kevin Millar, a .364 (4-for-11) lifetime hitter against Rivera. At 2-1, Rivera retired Millar on a pop to short as the huge crowd and Yankees dugout exhaled loudly.

Matsui’s fifth RBI came on a two-out single off Tim Wakefield in the sixth, an inning Kenny Lofton opened with a homer to right.

Mussina’s perfect-game bid vanished with one out in the seventh when Mark Bellhorn drove an opposite-field double to left-center with one out. Until Bellhorn’s two-bagger, Mussina retired the first 19 batters.

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Mike Mussina outpitched Curt Schilling in the Yankees’ 8-5 win over the Red Sox last night in Game 1 of the ALCS at the Stadium.